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  1. ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract α‐substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in natural products and pharmaceuticals. We report the α‐acetylation of C(sp3)−H substrates R−H with arylmethyl ketones ArC(O)Me to provide α‐alkylated ketones ArC(O)CH2R at RT withtBuOOtBu as oxidant via copper(I) ‐diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α‐substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [CuII](CH2C(O)Ar) that capture alkyl radicals R• to give R−CH2C(O)Ar outcompeting dimerization of the copper(II) enolate to give the 1,4‐diketone ArC(O)CH2CH2C(O)Ar. 
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  2. ; ; (, Chemical Science)
    The prenyl group is present in numerous biologically active small molecule drugs and natural products. We introduce benzylic C-H alkenylation of substrates Ar-CH3 with alkenylboronic esters (CH2)3O2B-CH=CMe2 as a pathway to form prenyl functionalized arenes Ar-CH2CH=CMe2. Mechanistic studies of this radical relay catalytic protocol reveal diverse reactivity pathways exhibited by the copper(II) vinyl intermediate [CuII]-CH=CMe2 that involve radical capture, bimolecular C-C bond formation, and hydrogen atom transfer (HAT). 
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  3. ; ; ; (, ACS Catalysis)
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  4. ; ; ; (, ACS catalysis)
    The methyl moiety is a key functional group that can result in major improvements in the potency and selectivity of pharmaceutical agents. We present a radical relay C–H methylation methodology that employs a β-diketiminate copper catalyst capable of methylating unactivated C(sp3)–H bonds. Taking advantage of the bench-stable DABAL-Me3, an amine-stabilized trimethylaluminum reagent, methylation of a range of substrates possessing both activated and unactivated C(sp3)–H bonds proceeds with a minimal amount of overmethylation. Mechanistic studies supported by both experiment and computation suggest the intermediacy of a copper(II) methyl intermediate reactive toward both the loss of the methyl radical as well capture of radicals R• to form R–Me bonds. 
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